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<script>
    var arr1 = [1, 2, 3, 4, 5];
    //（1）@@@在数组最后添加一个元素,传参为要添加的元素。(可传参)
    var jieguo1 = arr1.push(1, 2);
    console.log(arr1); //[1,2,3,4,5,1,2]//原来数组会被改变
    console.log(jieguo1); //7//@@@返回一个数组的新长度
</script>

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